The kidney in liver transplantation

Renal dysfunction often complicates the course of liver transplant recipients. Preoperative renal dysfunction, including hepatorenal syndrome (HRS) may be present. Assessment of renal function in the pretransplant patient with end-stage liver disease is fraught with pitfalls. Direct measurement of GFR by a method other than creatinine clearance is recommended wherever possible. Preoperative renal biopsy should also be considered in those patients with renal dysfunction in whom the diagnosis of HRS is not definite. With the routine use of veno venous bypass, renal perfusion is maintained and intraoperative events generally do not play a significant role in the development of postoperative dysfunction. Postoperatively immunosuppressive medications such as CsA or FK506 account for most of the renal dysfunction that is observed. Other factors such as graft dysfunction, sepsis, and nephrotoxic drugs may also participate in renal impairment. The exact mechanism of cyclosporine or FK506 nephrotoxicity remains unknown. In liver transplant recipients, no convincing therapeutic strategies exist to combat nephrotoxicity other than dose reduction of immunosuppressive therapy. Patients with HRS can be successfully treated by liver transplantation with recovery of renal function and with patient survival rates comparable to recipients without HRS, despite increased morbidity.